func main(f func(App)) {
runtime.LockOSThread()
C.createWindow()
// TODO: send lifecycle events when e.g. the X11 window is iconified or moved off-screen.
sendLifecycle(lifecycle.StageFocused)
donec := make(chan struct{})
go func() {
f(app{})
close(donec)
}()
// TODO: can we get the actual vsync signal?
ticker := time.NewTicker(time.Second / 60)
defer ticker.Stop()
tc := ticker.C
for {
select {
case <-donec:
return
case <-gl.WorkAvailable:
gl.DoWork()
case <-endPaint:
C.swapBuffers()
tc = ticker.C
case <-tc:
tc = nil
eventsIn <- paint.Event{}
}
C.processEvents()
}
}
// loop is the primary drawing loop.
//
// After Cocoa has captured the initial OS thread for processing Cocoa
// events in runApp, it starts loop on another goroutine. It is locked
// to an OS thread for its OpenGL context.
//
// Two Cocoa threads deliver draw signals to loop. The primary source of
// draw events is the CVDisplayLink timer, which is tied to the display
// vsync. Secondary draw events come from [NSView drawRect:] when the
// window is resized.
func loop(ctx C.GLintptr) {
runtime.LockOSThread()
C.makeCurrentContext(ctx)
for range draw {
eventsIn <- paint.Event{}
loop1:
for {
select {
case <-gl.WorkAvailable:
gl.DoWork()
case <-endPaint:
C.CGLFlushDrawable(C.CGLGetCurrentContext())
break loop1
}
}
drawDone <- struct{}{}
}
}
//export drawgl
func drawgl(ctx uintptr) {
if !startedgl {
startedgl = true
C.setContext(unsafe.Pointer(ctx))
// TODO(crawshaw): not just on process start.
sendLifecycle(lifecycle.StageFocused)
}
eventsIn <- paint.Event{}
for {
select {
case <-gl.WorkAvailable:
gl.DoWork()
case <-endPaint:
return
}
}
}
func TestImage(t *testing.T) {
done := make(chan error)
defer close(done)
go func() {
runtime.LockOSThread()
ctx, err := createContext()
done <- err
for {
select {
case <-gl.WorkAvailable:
gl.DoWork()
case <-done:
ctx.destroy()
return
}
}
}()
if err := <-done; err != nil {
t.Fatalf("cannot create GL context: %v", err)
}
start()
defer stop()
// GL testing strategy:
// 1. Create an offscreen framebuffer object.
// 2. Configure framebuffer to render to a GL texture.
// 3. Run test code: use glimage to draw testdata.
// 4. Copy GL texture back into system memory.
// 5. Compare to a pre-computed image.
f, err := os.Open("../../../testdata/testpattern.png")
if err != nil {
t.Fatal(err)
}
defer f.Close()
src, _, err := image.Decode(f)
if err != nil {
t.Fatal(err)
}
const (
pixW = 100
pixH = 100
ptW = geom.Pt(50)
ptH = geom.Pt(50)
)
sz := size.Event{
WidthPx: pixW,
HeightPx: pixH,
WidthPt: ptW,
HeightPt: ptH,
PixelsPerPt: float32(pixW) / float32(ptW),
}
fBuf := gl.CreateFramebuffer()
gl.BindFramebuffer(gl.FRAMEBUFFER, fBuf)
colorBuf := gl.CreateRenderbuffer()
gl.BindRenderbuffer(gl.RENDERBUFFER, colorBuf)
// https://www.khronos.org/opengles/sdk/docs/man/xhtml/glRenderbufferStorage.xml
// says that the internalFormat "must be one of the following symbolic constants:
// GL_RGBA4, GL_RGB565, GL_RGB5_A1, GL_DEPTH_COMPONENT16, or GL_STENCIL_INDEX8".
gl.RenderbufferStorage(gl.RENDERBUFFER, gl.RGB565, pixW, pixH)
gl.FramebufferRenderbuffer(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.RENDERBUFFER, colorBuf)
if status := gl.CheckFramebufferStatus(gl.FRAMEBUFFER); status != gl.FRAMEBUFFER_COMPLETE {
t.Fatalf("framebuffer create failed: %v", status)
}
allocs := testing.AllocsPerRun(100, func() {
gl.ClearColor(0, 0, 1, 1) // blue
})
if allocs != 0 {
t.Errorf("unexpected allocations from calling gl.ClearColor: %f", allocs)
}
gl.Clear(gl.COLOR_BUFFER_BIT)
gl.Viewport(0, 0, pixW, pixH)
m := NewImage(src.Bounds().Dx(), src.Bounds().Dy())
b := m.RGBA.Bounds()
draw.Draw(m.RGBA, b, src, src.Bounds().Min, draw.Src)
m.Upload()
b.Min.X += 10
b.Max.Y /= 2
// All-integer right-angled triangles offsetting the
// box: 24-32-40, 12-16-20.
ptTopLeft := geom.Point{0, 24}
ptTopRight := geom.Point{32, 0}
ptBottomLeft := geom.Point{12, 24 + 16}
ptBottomRight := geom.Point{12 + 32, 16}
m.Draw(sz, ptTopLeft, ptTopRight, ptBottomLeft, b)
// For unknown reasons, a windowless OpenGL context renders upside-
// down. That is, a quad covering the initial viewport spans:
//
// (-1, -1) ( 1, -1)
// (-1, 1) ( 1, 1)
//
// To avoid modifying live code for tests, we flip the rows
// recovered from the renderbuffer. We are not the first:
//
// http://lists.apple.com/archives/mac-opengl/2010/Jun/msg00080.html
got := image.NewRGBA(image.Rect(0, 0, pixW, pixH))
upsideDownPix := make([]byte, len(got.Pix))
gl.ReadPixels(upsideDownPix, 0, 0, pixW, pixH, gl.RGBA, gl.UNSIGNED_BYTE)
for y := 0; y < pixH; y++ {
i0 := (pixH - 1 - y) * got.Stride
i1 := i0 + pixW*4
copy(got.Pix[y*got.Stride:], upsideDownPix[i0:i1])
}
drawCross(got, 0, 0)
drawCross(got, int(ptTopLeft.X.Px(sz.PixelsPerPt)), int(ptTopLeft.Y.Px(sz.PixelsPerPt)))
drawCross(got, int(ptBottomRight.X.Px(sz.PixelsPerPt)), int(ptBottomRight.Y.Px(sz.PixelsPerPt)))
drawCross(got, pixW-1, pixH-1)
const wantPath = "../../../testdata/testpattern-window.png"
f, err = os.Open(wantPath)
if err != nil {
t.Fatal(err)
}
defer f.Close()
wantSrc, _, err := image.Decode(f)
if err != nil {
t.Fatal(err)
}
want, ok := wantSrc.(*image.RGBA)
if !ok {
b := wantSrc.Bounds()
want = image.NewRGBA(b)
draw.Draw(want, b, wantSrc, b.Min, draw.Src)
}
if !imageEq(got, want) {
// Write out the image we got.
f, err = ioutil.TempFile("", "testpattern-window-got")
if err != nil {
t.Fatal(err)
}
f.Close()
gotPath := f.Name() + ".png"
f, err = os.Create(gotPath)
if err != nil {
t.Fatal(err)
}
if err := png.Encode(f, got); err != nil {
t.Fatal(err)
}
if err := f.Close(); err != nil {
t.Fatal(err)
}
t.Errorf("got\n%s\nwant\n%s", gotPath, wantPath)
}
}
func main(f func(App)) {
// Preserve this OS thread for:
// 1. the attached JNI thread
// 2. the GL context
runtime.LockOSThread()
// Calls into NativeActivity functions must be made from
// a thread attached to the JNI.
var env *C.JNIEnv
if errStr := C.attachJNI(&env); errStr != nil {
log.Fatalf("app: %s", C.GoString(errStr))
}
donec := make(chan struct{})
go func() {
f(app{})
close(donec)
}()
var q *C.AInputQueue
var pixelsPerPt float32
var orientation size.Orientation
// Android can send a windowRedrawNeeded event any time, including
// in the middle of a paint cycle. The redraw event may have changed
// the size of the screen, so any partial painting is now invalidated.
// We must also not return to Android (via sending on windowRedrawDone)
// until a complete paint with the new configuration is complete.
//
// When a windowRedrawNeeded request comes in, we increment redrawGen
// (Gen is short for generation number), and do not make a paint cycle
// visible on <-endPaint unless Generation agrees. If possible,
// windowRedrawDone is signalled, allowing onNativeWindowRedrawNeeded
// to return.
var redrawGen uint32
for {
if q != nil {
processEvents(env, q)
}
select {
case <-windowCreated:
case q = <-inputQueue:
case <-donec:
return
case cfg := <-windowConfigChange:
pixelsPerPt = cfg.pixelsPerPt
orientation = cfg.orientation
case w := <-windowRedrawNeeded:
if C.surface == nil {
if errStr := C.createEGLSurface(w); errStr != nil {
log.Printf("app: %s (%s)", C.GoString(errStr), eglGetError())
return
}
}
sendLifecycle(lifecycle.StageFocused)
widthPx := int(C.ANativeWindow_getWidth(w))
heightPx := int(C.ANativeWindow_getHeight(w))
eventsIn <- size.Event{
WidthPx: widthPx,
HeightPx: heightPx,
WidthPt: geom.Pt(float32(widthPx) / pixelsPerPt),
HeightPt: geom.Pt(float32(heightPx) / pixelsPerPt),
PixelsPerPt: pixelsPerPt,
Orientation: orientation,
}
redrawGen++
eventsIn <- paint.Event{redrawGen}
case <-windowDestroyed:
if C.surface != nil {
if errStr := C.destroyEGLSurface(); errStr != nil {
log.Printf("app: %s (%s)", C.GoString(errStr), eglGetError())
return
}
}
C.surface = nil
sendLifecycle(lifecycle.StageAlive)
case <-gl.WorkAvailable:
gl.DoWork()
case p := <-endPaint:
if p.Generation != redrawGen {
continue
}
if C.surface != nil {
// eglSwapBuffers blocks until vsync.
if C.eglSwapBuffers(C.display, C.surface) == C.EGL_FALSE {
log.Printf("app: failed to swap buffers (%s)", eglGetError())
}
}
select {
case windowRedrawDone <- struct{}{}:
default:
}
if C.surface != nil {
redrawGen++
eventsIn <- paint.Event{redrawGen}
}
}
}
}